diff mbox

[v3,5/5] mtd: spi-nor: cadence-quadspi: Add runtime PM support

Message ID 20170924105924.23923-6-vigneshr@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Vignesh Raghavendra Sept. 24, 2017, 10:59 a.m. UTC
Add pm_runtime* calls to cadence-quadspi driver. This is required to
switch on QSPI power domain on TI 66AK2G SoC during probe.

Signed-off-by: Vignesh R <vigneshr@ti.com>
---
 drivers/mtd/spi-nor/cadence-quadspi.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

Marek Vasut Sept. 24, 2017, 12:01 p.m. UTC | #1
On 09/24/2017 12:59 PM, Vignesh R wrote:
> Add pm_runtime* calls to cadence-quadspi driver. This is required to
> switch on QSPI power domain on TI 66AK2G SoC during probe.
> 
> Signed-off-by: Vignesh R <vigneshr@ti.com>

Are you planning to add some more fine-grained PM control later?

> ---
>  drivers/mtd/spi-nor/cadence-quadspi.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
> index d9629e8f4798..2c8e6226d267 100644
> --- a/drivers/mtd/spi-nor/cadence-quadspi.c
> +++ b/drivers/mtd/spi-nor/cadence-quadspi.c
> @@ -31,6 +31,7 @@
>  #include <linux/of_device.h>
>  #include <linux/of.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/sched.h>
>  #include <linux/spi/spi.h>
>  #include <linux/timer.h>
> @@ -1224,6 +1225,13 @@ static int cqspi_probe(struct platform_device *pdev)
>  		return -ENXIO;
>  	}
>  
> +	pm_runtime_enable(&pdev->dev);
> +	ret = pm_runtime_get_sync(&pdev->dev);
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(&pdev->dev);
> +		return ret;
> +	}
> +
>  	ret = clk_prepare_enable(cqspi->clk);
>  	if (ret) {
>  		dev_err(dev, "Cannot enable QSPI clock.\n");
> @@ -1275,6 +1283,9 @@ static int cqspi_remove(struct platform_device *pdev)
>  
>  	clk_disable_unprepare(cqspi->clk);
>  
> +	pm_runtime_put_sync(&pdev->dev);
> +	pm_runtime_disable(&pdev->dev);
> +
>  	return 0;
>  }
>  
>
Vignesh Raghavendra Sept. 24, 2017, 1:08 p.m. UTC | #2
On 9/24/2017 5:31 PM, Marek Vasut wrote:
> On 09/24/2017 12:59 PM, Vignesh R wrote:
>> Add pm_runtime* calls to cadence-quadspi driver. This is required to
>> switch on QSPI power domain on TI 66AK2G SoC during probe.
>>
>> Signed-off-by: Vignesh R <vigneshr@ti.com>
> 
> Are you planning to add some more fine-grained PM control later?

Yes, I will need to add fine-grained PM control at some point. But, for
now SoC does not really support low power mode or runtime power saving
option.
The fact that driver still uses clk_prepare_*() calls to enable/disable
clocks instead of pm_*() calls makes it a bit tricky though.

Just figured out I forgot to add cleanup code in error handling path of
probe(). Will fix that and send a v4.

> 
>> ---
>>  drivers/mtd/spi-nor/cadence-quadspi.c | 11 +++++++++++
>>  1 file changed, 11 insertions(+)
>>
>> diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
>> index d9629e8f4798..2c8e6226d267 100644
>> --- a/drivers/mtd/spi-nor/cadence-quadspi.c
>> +++ b/drivers/mtd/spi-nor/cadence-quadspi.c
>> @@ -31,6 +31,7 @@
>>  #include <linux/of_device.h>
>>  #include <linux/of.h>
>>  #include <linux/platform_device.h>
>> +#include <linux/pm_runtime.h>
>>  #include <linux/sched.h>
>>  #include <linux/spi/spi.h>
>>  #include <linux/timer.h>
>> @@ -1224,6 +1225,13 @@ static int cqspi_probe(struct platform_device *pdev)
>>  		return -ENXIO;
>>  	}
>>  
>> +	pm_runtime_enable(&pdev->dev);
>> +	ret = pm_runtime_get_sync(&pdev->dev);
>> +	if (ret < 0) {
>> +		pm_runtime_put_noidle(&pdev->dev);
>> +		return ret;
>> +	}
>> +
>>  	ret = clk_prepare_enable(cqspi->clk);
>>  	if (ret) {
>>  		dev_err(dev, "Cannot enable QSPI clock.\n");
>> @@ -1275,6 +1283,9 @@ static int cqspi_remove(struct platform_device *pdev)
>>  
>>  	clk_disable_unprepare(cqspi->clk);
>>  
>> +	pm_runtime_put_sync(&pdev->dev);
>> +	pm_runtime_disable(&pdev->dev);
>> +
>>  	return 0;
>>  }
>>  
>>
> 
>
Marek Vasut Sept. 24, 2017, 1:12 p.m. UTC | #3
On 09/24/2017 03:08 PM, Vignesh R wrote:
> 
> 
> On 9/24/2017 5:31 PM, Marek Vasut wrote:
>> On 09/24/2017 12:59 PM, Vignesh R wrote:
>>> Add pm_runtime* calls to cadence-quadspi driver. This is required to
>>> switch on QSPI power domain on TI 66AK2G SoC during probe.
>>>
>>> Signed-off-by: Vignesh R <vigneshr@ti.com>
>>
>> Are you planning to add some more fine-grained PM control later?
> 
> Yes, I will need to add fine-grained PM control at some point. But, for
> now SoC does not really support low power mode or runtime power saving
> option.
> The fact that driver still uses clk_prepare_*() calls to enable/disable
> clocks instead of pm_*() calls makes it a bit tricky though.
> 
> Just figured out I forgot to add cleanup code in error handling path of
> probe(). Will fix that and send a v4.

OK, fine. Cleanups are welcome. The SoCFPGA doesn't do much runtime PM
either, so it's fine for now.
Vignesh Raghavendra Sept. 24, 2017, 1:27 p.m. UTC | #4
On 9/24/2017 6:42 PM, Marek Vasut wrote:
> On 09/24/2017 03:08 PM, Vignesh R wrote:
>>
>>
>> On 9/24/2017 5:31 PM, Marek Vasut wrote:
>>> On 09/24/2017 12:59 PM, Vignesh R wrote:
>>>> Add pm_runtime* calls to cadence-quadspi driver. This is required to
>>>> switch on QSPI power domain on TI 66AK2G SoC during probe.
>>>>
>>>> Signed-off-by: Vignesh R <vigneshr@ti.com>
>>>
>>> Are you planning to add some more fine-grained PM control later?
>>
>> Yes, I will need to add fine-grained PM control at some point. But, for
>> now SoC does not really support low power mode or runtime power saving
>> option.
>> The fact that driver still uses clk_prepare_*() calls to enable/disable
>> clocks instead of pm_*() calls makes it a bit tricky though.
>>
>> Just figured out I forgot to add cleanup code in error handling path of
>> probe(). Will fix that and send a v4.
> 
> OK, fine. Cleanups are welcome. The SoCFPGA doesn't do much runtime PM
> either, so it's fine for now.
> 

Ok thanks! Do you know if pm_runtime_get_sync() can enable clocks for
QSPI on SoCFPGA or if clk_prepare_enable() is needed? Just trying to see
if its possible to get rid of clk_*() calls in favor of pm_*() calls.
Marek Vasut Sept. 24, 2017, 1:51 p.m. UTC | #5
On 09/24/2017 03:27 PM, Vignesh R wrote:
> 
> 
> On 9/24/2017 6:42 PM, Marek Vasut wrote:
>> On 09/24/2017 03:08 PM, Vignesh R wrote:
>>>
>>>
>>> On 9/24/2017 5:31 PM, Marek Vasut wrote:
>>>> On 09/24/2017 12:59 PM, Vignesh R wrote:
>>>>> Add pm_runtime* calls to cadence-quadspi driver. This is required to
>>>>> switch on QSPI power domain on TI 66AK2G SoC during probe.
>>>>>
>>>>> Signed-off-by: Vignesh R <vigneshr@ti.com>
>>>>
>>>> Are you planning to add some more fine-grained PM control later?
>>>
>>> Yes, I will need to add fine-grained PM control at some point. But, for
>>> now SoC does not really support low power mode or runtime power saving
>>> option.
>>> The fact that driver still uses clk_prepare_*() calls to enable/disable
>>> clocks instead of pm_*() calls makes it a bit tricky though.
>>>
>>> Just figured out I forgot to add cleanup code in error handling path of
>>> probe(). Will fix that and send a v4.
>>
>> OK, fine. Cleanups are welcome. The SoCFPGA doesn't do much runtime PM
>> either, so it's fine for now.
>>
> 
> Ok thanks! Do you know if pm_runtime_get_sync() can enable clocks for
> QSPI on SoCFPGA or if clk_prepare_enable() is needed? Just trying to see
> if its possible to get rid of clk_*() calls in favor of pm_*() calls.

Not of the top of my head, sorry. +CC Matthew, he should know.
Matthew Gerlach Sept. 25, 2017, 10:41 p.m. UTC | #6
On Sun, 24 Sep 2017, Marek Vasut wrote:

> On 09/24/2017 03:27 PM, Vignesh R wrote:
>>
>>
>> On 9/24/2017 6:42 PM, Marek Vasut wrote:
>>> On 09/24/2017 03:08 PM, Vignesh R wrote:
>>>>
>>>>
>>>> On 9/24/2017 5:31 PM, Marek Vasut wrote:
>>>>> On 09/24/2017 12:59 PM, Vignesh R wrote:
>>>>>> Add pm_runtime* calls to cadence-quadspi driver. This is required to
>>>>>> switch on QSPI power domain on TI 66AK2G SoC during probe.
>>>>>>
>>>>>> Signed-off-by: Vignesh R <vigneshr@ti.com>
>>>>>
>>>>> Are you planning to add some more fine-grained PM control later?
>>>>
>>>> Yes, I will need to add fine-grained PM control at some point. But, for
>>>> now SoC does not really support low power mode or runtime power saving
>>>> option.
>>>> The fact that driver still uses clk_prepare_*() calls to enable/disable
>>>> clocks instead of pm_*() calls makes it a bit tricky though.
>>>>
>>>> Just figured out I forgot to add cleanup code in error handling path of
>>>> probe(). Will fix that and send a v4.
>>>
>>> OK, fine. Cleanups are welcome. The SoCFPGA doesn't do much runtime PM
>>> either, so it's fine for now.
>>>
>>
>> Ok thanks! Do you know if pm_runtime_get_sync() can enable clocks for
>> QSPI on SoCFPGA or if clk_prepare_enable() is needed? Just trying to see
>> if its possible to get rid of clk_*() calls in favor of pm_*() calls.
>
> Not of the top of my head, sorry. +CC Matthew, he should know.

I am not an expert at the clock framework nor the power management, but I
did ask around a bit.  No one I asked was planning to change the clk_*()
calls to pm_*() call, but the feedback was that it would be a good idea.

Matthew Gerlach


>
> -- 
> Best regards,
> Marek Vasut
>
Marek Vasut Sept. 25, 2017, 11:49 p.m. UTC | #7
On 09/26/2017 12:41 AM, matthew.gerlach@linux.intel.com wrote:
> 
> 
> On Sun, 24 Sep 2017, Marek Vasut wrote:
> 
>> On 09/24/2017 03:27 PM, Vignesh R wrote:
>>>
>>>
>>> On 9/24/2017 6:42 PM, Marek Vasut wrote:
>>>> On 09/24/2017 03:08 PM, Vignesh R wrote:
>>>>>
>>>>>
>>>>> On 9/24/2017 5:31 PM, Marek Vasut wrote:
>>>>>> On 09/24/2017 12:59 PM, Vignesh R wrote:
>>>>>>> Add pm_runtime* calls to cadence-quadspi driver. This is required to
>>>>>>> switch on QSPI power domain on TI 66AK2G SoC during probe.
>>>>>>>
>>>>>>> Signed-off-by: Vignesh R <vigneshr@ti.com>
>>>>>>
>>>>>> Are you planning to add some more fine-grained PM control later?
>>>>>
>>>>> Yes, I will need to add fine-grained PM control at some point. But,
>>>>> for
>>>>> now SoC does not really support low power mode or runtime power saving
>>>>> option.
>>>>> The fact that driver still uses clk_prepare_*() calls to
>>>>> enable/disable
>>>>> clocks instead of pm_*() calls makes it a bit tricky though.
>>>>>
>>>>> Just figured out I forgot to add cleanup code in error handling
>>>>> path of
>>>>> probe(). Will fix that and send a v4.
>>>>
>>>> OK, fine. Cleanups are welcome. The SoCFPGA doesn't do much runtime PM
>>>> either, so it's fine for now.
>>>>
>>>
>>> Ok thanks! Do you know if pm_runtime_get_sync() can enable clocks for
>>> QSPI on SoCFPGA or if clk_prepare_enable() is needed? Just trying to see
>>> if its possible to get rid of clk_*() calls in favor of pm_*() calls.
>>
>> Not of the top of my head, sorry. +CC Matthew, he should know.
> 
> I am not an expert at the clock framework nor the power management, but I
> did ask around a bit.  No one I asked was planning to change the clk_*()
> calls to pm_*() call, but the feedback was that it would be a good idea.

The question is, if we do the replacement, will it break on socfpga ?
A quick test might be useful.
diff mbox

Patch

diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
index d9629e8f4798..2c8e6226d267 100644
--- a/drivers/mtd/spi-nor/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -31,6 +31,7 @@ 
 #include <linux/of_device.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/sched.h>
 #include <linux/spi/spi.h>
 #include <linux/timer.h>
@@ -1224,6 +1225,13 @@  static int cqspi_probe(struct platform_device *pdev)
 		return -ENXIO;
 	}
 
+	pm_runtime_enable(&pdev->dev);
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(&pdev->dev);
+		return ret;
+	}
+
 	ret = clk_prepare_enable(cqspi->clk);
 	if (ret) {
 		dev_err(dev, "Cannot enable QSPI clock.\n");
@@ -1275,6 +1283,9 @@  static int cqspi_remove(struct platform_device *pdev)
 
 	clk_disable_unprepare(cqspi->clk);
 
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
 	return 0;
 }